Like many other MCU flicks, Thor: Ragnarok is one of the most anticipated movies of the year. Directed by Taika Waititi, it’s most likely the final installment of this solo franchise. Furthermore, it will feature a host of new characters, as well as cameos by other Avengers, most notably Doctor Strange. Talking about this, Kevin Feige revealed that the Sorcerer Supreme's role may not be as big as fans believe:
I don't know about branching off from this, but certainly inhabiting similar areas from this. A lot of our upcoming movies will. I mean the upcoming movies will be as much up here, as they are on Earth, starting with not Spider-Man, starting with Thor: Ragnarok.
There are three scenes on Earth in Thor: Ragnarok. Everything else is Asgard, and not all of these worlds, but world that certainly, let's put it this way, in Thor lingo, it's beyond the nine realms. There are other planets that we spend a lot of time on in Thor: Ragnarok, that certainly people would say, “Oh, that's sort of like the Guardians’ world”, but they're just other areas of the Marvel cosmos universe. (via CBM)
Basically, Thor: Ragnarok may seem to copy other MCU movies, but it will be essentially unique. It will differentiate itself, not just from the Marvel flicks released so far, but also from the previous Thor movies. And given the way the previous movies were received, this can only be for the better.
As far as Doctor Strange is concerned, if he doesn't go off-world, we might see him in just one scene in Thor: Ragnarok. But it remains to be seen - previous rumors said that he'll have a consistent role.
We'll wait and see. Thor: Ragnarok will hit the big screen on the 3rd of November.